The confrontation happened after interim coach Lindsey Hunter's first practice and unfolded within earshot of several Suns players in the locker room, sources said.

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O'Neal is frustrated with the direction of the Suns' rebuild and wanted more clarity on his future this season, a source with knowledge of the confrontation said. At 13-28, the Suns have the worst record in the Western Conference.

O'Neal signed a one-year deal in the offseason with Phoenix.

The Arizona Republic reported Tuesday that O'Neal missed practice with an "unstated medical issue" and wouldn't make the team's trip to Sacramento.